[Heath] Teeny screws for Amphenol microphone connector

[John Klingelhoeffer]

Hi Sandy;


I took one of the connectors I have in the junque boxe, removed the screw in question, and it measures as follows:


Diameter of head:  0.153"


Total length:  0.175"


Across threads:  0.086" dia


Threaded stock length:  0.113" (approximately)


The threads are machine and not tapered, nor is the screw pointed - the end is flat.  I will note that I have NOT put it under a microscope and counted threads per inch.  It is certainly not a self-tapping or thread-cutting screw. 




When comparing this to something available at McMaster, about the closest thing is a 2-56 flat head machine screw.  That has threads that are 0.086" in diameter, and a head of 0.162".  The size 1-72 screw is markedly smaller in each dimension.  I am guessing since it is (was) manufactured by Amphenol in Chicago at the time, that it was not metric.  


A problem for easily available screws from McMaster is the length.  2-56  FH is available in 1/8", 5/32" and 3/16" length, none of which are 0.175" long.  I don't have any idea how deep the hole goes or is tapped.  Probably a bit longer than the original screw.  I guess you could try the 3/16" long, and if it will not fit, you could file the end down some to get it to 0.175" or so.  


On mine, the flat head recesses quite a bit into the connector, so the difference between 153 and 162 thousandths is probably de minimus.  May even take care of the extra length of the 3/16 screw.  


The zinc-plated steel units from McMaster have part number 
90273A050,  $2.76 per 100.  They also offer them in two varieties of stainless steel if you are going to keep the rig for three lifetimes.  The 18-8 is only about twice the price, but 316 SS is about quadruple.  Maybe you have a local model airplane shop that has them in smaller quantities, but I wouldn't hunt to long to save $2.76!  Ebay doesn't seem to be any cheaper, and has less selection.


I also have one connector in the junque boxe missing a screw, but no telling how long it will be until I use it.  I'm not sure I have any green boxes that have that mating chassis connector on them anymore.  


Have a good holiday.  Keep the green boxes glowing.


73


John...
WB4LNM


"One of the Hams from Heath"


Message: 1
Date: Tue, 24 Nov 2015 15:06:21 -0500
From: "Alexander N. Gerli" <ac1wye at gmail.com>
To: heath at puck.nether.net
Cc: heathkit at mailman.qth.net
Subject: [Heath] teeny tiny screws WTD
Message-ID:
	<CACs0R21qU6YVqk6Nwjn2x_TB1Kqco6NSz-t8wifa0A0eE+rNaQ at mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

Hi, gang!  You all know the LITTLE flat-head short screw in the
Heathkit/Amphenol 80MC2M mic connector, the one which holds the plastic
connector and pins inside the shell? Some Straight, some Philips.

Well, I find in my connector stash that I have three complete connectors
that are MISSING that darn little screw (Finagle's Corollary to Murphy's
Law). I know of a few places to look, BUT that's not much help unless I can
identify the screw by its size. What is it? a #0 or a #1 maybe? Probably
1/8" long. Does anybody on the List know?

?73,?


?Sandy AC1Y?


Alexander N. Gerli, Sr.
548 Allred Mill Road
Mount Airy, NC 27030-2202



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://puck.nether.net/pipermail/heath/attachments/20151125/5a078fb1/attachment-0001.html>